Containers and method of making same



June 12, 1956 G. A. MOORE CONTAINERS AND METHOD OF MAKING SAME 3 Sheets-Sheet 1 Filed July 16, 1952 INVENTOR.

June 12, 1956 e. A. MOORE 2,750,097

CONTAINERS AND METHOD OF MAKING SAME Filed July 16, 1952 3 Sheets-Sheet 2 IN VEN TOR.

N E Q E June 12, 1956 G. A. MOORE CONTAINERS AND METHOD OF MAKING SAME 3 Sheets-Sheet 5 Filed July 16, 1952 INVENTOR.

United States Patent Ofilce This invention relates to hermetic containers and to methods employed for fabricating same. The containers are primarily made of paper board and aluminum, the latter material being employed in forming an hermetic closure to the container after filling same.

One of the objects of the present invention is to provide a sanitary container adapted to carry liquids and hygroscopic products, the container having an integral-and initially hermetically sealed dispensing closure.

Another object of the instant invention is to provide a paper board container having an aluminum hermetically sealed end closure, the closure being formed and sealed by a simple method in substantially one station of operaman.

A further object of this invention is to provide a method of forming rectangular shaped containers having either straight side walls or tapered walls, the latter shape of the Walls facilitating the nesting together of empty containers to provide economy in storage and shipping costs.

A still further object of the invention is to provide containers which are constructed in such manner that raw edges of material within the interior of the container is avoided.

Still another object of the instant invention is to provide a method of forming combination seam structures in containers, the seams comprising, abutments of material sealed in edge to face engagements and further sealed in overlapping relationship.

These and other objects of the invention will be apparent upon reading the following descriptive disclosure read in conjunction with the illustrative accompanying drawings, wherein;

Fig. 1 is a plan view of a first blank used in constructing the container,

Fig. 2 is a perspective view of the first blank formed over three sides of a form,

Fig. 3 is a plan view of a second blank,

Fig. 4 is a perspective view of the second blank formed in superimposing relationship with the first blank,

Fig. 5 is a fragmentary View in cross-section taken on line 55 of Fig. 4,

Fig. 6 is an elevation of seam forming tools with the form and assembled blanks in cross-section taken on line a-a in Fig. 4,

Fig. 7 is an elevation of a further position of the tools in Fig. 6,

Fig. 8 is a fragmentary enlarged view in cross-section of a seam of the container taken on a part of the line 11-11 in Fig. 4,

Fig. 9 is an end view partly in cross-section of the form in engagement with other tools,

Fig. 10 is a fragmentary plan view of a strip of alumi- 2,750,097 Patented June 12, 1956 Fig. 13 is a fragmentary enlarged view in cross-section of the closure taken on line 13-13 in Fig. 12,

Fig. 14 is a perspective view of the completed container, and,

Fig. 15 is a fragmentary view in perspective of the container with its dispensing closure in open position.

The container shown in the drawings is illustrated with tapering sides to enable the empty containers to nest each within the other like container and provide sanitary condition as well as economy of transportation. The containers may be made with straight sides when they are fabricated in user plants.

The material which provides the container blanks is preferably paper or paper-board, the interior walls may be treated after the containers are fabricated prior to capping or, the paper-board may be coated with thermoplastic film suchas polyethylene, Saran or vinyl compositions or other suitable material prior to the fabrication of the containers. The container blanks are cut from printed rolls of sheet material. A first blank4 (Fig. l) is provided with a central base area 5 defined with parallel folding lines 6 and parallel transversely disposed sides 7. The blank is also provided with oppositely disposed lateral extending panel areas 8 having tapering opposed sides 9 and opposite ends 10 disposed in parallel relationship. The central area 5 is provided with substantially U-shaped cut lines 11 constituting a severable tongue area portion 12. The blank 4 may be provided on one side thereof with a thermoplastic film of suitable material.

The first blank 4 is positioned to a form 13 (Fig. 2) the central base area 5 of the blank being centrally located to match the rectangular shaped end of the form 13. The lateral extensions 8 of the blank are folded on the parallel lines 6 at near right angles over the top and bottom sides of the form. The sides 7 and 9 of the folded blank are located substantially flush with the opposed uncovered side walls of the form. Dot and dash lines 14 shown on the exterior surfaces of the folded blank 4 define areas that extend outwardly therefrom to the sides of the blanks 7 and 9, the said areas constituting the seam locating zones to the folded blank when fabricating the container. When fabricating containers of plain paper board (uncoated) these zone areas constitute a pattern for printing a thermoplastic adhesive on the surface of the blank prior to the assembly of the blank to the form. The said zone areas include the area of the tongue 12.

The second blank 15 (Fig. 3) is provided with a central base area 16 defined with parallel folding lines 17 and transversely disposed parallel folding lines 18. A flanged area constituting a flap 19, extends outwardly of the top fold line 17. The ilap is substantially separated from other areas of the flange by two opposed cut lines 21) disposed parallel with the top fold line 17 and radially cut lines 21 transversely disposed to each cut line 20 and terminating outwardly of the fold line 17. The said out lines 20 and 21 provide a pair of opposed tabs 24 having outwardly disposed edges 22 which slope at substantially 45 degrees and terminate by connections with edges 23 which are disposed outwardly of the folding line 17 and parallel thereto. A pair of opposed inwardly tapering perforated cut lines 25 extend from the top fold line 1'7 and terminate inwardly of the bottom folding line 17. A flange area 26 projects outwardly of the bottom fold line 17 and is provided with opposed sloping ends 27 disposed at substantially 45 degrees with edges 28 which are disposed outwardly of the bottom fold line 17 and parallel thereto.

Laterally disposed panel areas 29 extend outwardly in opposite directions from the transversely disposed folding lines 13. The panel areas 29 are defined with tapering folding lines 30 which begin at the corner junctions of the parallel folding lines i7 and i8 and slope outthe opposite ed rally from each other terminating at each opposite end e blank. The upper side of the panel areas 29 have flanged s "M eaten outwardly of the upper tapering folding linesfitl. The flanges have inner oppesed ends adjacent the centr l basearea l6 and are defined '-.vith sloping edges which form V-shapc notches with as the said notches having blunt apices 23 disposed or warcly of the top fold line 17. Fortiors E iot the flanges 32 slope slightlyupwardsincreasing the area of the flanges adiac ent to the sloping edges 33 and The opposite ends of the 3!- have slightly sloping edges 35 disposed at right angles to the tanering folding lines 3).

The panel areas .729 have lower flanged areas 36 disposed outward of the lower tapering folding lines 3 1' which have in ardly disposed sloping ends w ch form if-shaped notches with the opposite ed s having blunt apices-ZS disposed outwardly ofthe bottom fold line 17 nndpar-allel thereto. The opposite ends 350 are tapered toform a right :inglewith the folding lines 36. The outer edges '33 of the blank are substantially at right angles to the end edges 31 the blank. The blank 15 may be coated with thermoplastic film comparable to the coating on the blank 4. if the container is to be fabricated of plain board the thermoplastic adhesivc'for making the seams of the container may be provided on the first blank 4 hereinbefore described.

The second blank 25 is positioned to the form 13 (Fig. 4), the central area 36 of the blank superimposing the central area of the previously positioned and folded blank 4. The panel areas 25) of the second blank are folded to enclose the two exposed sides of the form previously provided with the first blank. The flap 19 and tabs 24 are folded on the upper fold line it? to overlap a marginal area of the top panel area 8 of the folded blank 4-. The flange 26 is folded to overlap a marginal area of the opposite lower panel area The longitudinal flanges 32 and 36 of the blank 35 are folded to overlap marginal areas of the panels 3 of the folded blank 4, the flange areas 3 the top side of the form overlapping side marginal areas of the folded flap E9. The V- shaped notches 22. 23, 33 and 27, 28, 37 are closed forming abutments (if, the blunt ap ces Z3 and 23 of the closed notches forming excess material if; at each of the four corners adjacent the end wall it? of the assembledcontainer. The edges 33a of the folded flange areas 34% are disposed in line with cut lines i the said areas 3% being disposed in a slightly upward inclining plane in opposed relationship.

The form 13 (Fig. 5) may be provided with suction holes 39 arranged through the walls of the form suitable to firmly retain the assembled blanks to the walls of the form by suction until the seams are formed the con tainer. The form may be provided with a strip pl. t 49 adapted to eject the completed container from the form. Air pressure may alternately he provided through the form if desired to accelerate the ejection of the assembled containers.

The method of folding and scaling the seams of the assembled blanks consists of a first step of compressing the superimposed layers of material comprising the central base areas 5 and of the assembled blanks land 3.5. A heated die 41 (Fig. 5) equipped with electrical heating cartridges or calrods #2, contacts the exterior face of the central area M of the assembled blank 15, heating and compressing concentrated areas of the material layers consisting of the tongue area 12 outlined by the cut lines 11 in the assembled blank 4 and the areas defined by perforated cut lines in the end wall 16 and outwardly to corners 13 thereof and the area disposed between the groove 43 and lower corner 17. The die 41 cmbosses a groove 43 extending across the ends of the cut lines 11 and 25, the ends of the groove terminating slightly outwards of the cut lines 25. The areas disposed between the cut lines 11 and 25 are lightly compressed,

the face of the die 41 being slightly relieved over the said areas. The tongue'lZ is united with the central area of the end Wall 16, the areas outwardly of the cut lines 25 and groove 43 are united together. The uniting of the wall areas takes place by the action of pressure and heat imparted to the material by the die 41 which activates the thermoplastic film adhesive previously applied to the blank material.

The die 41 remains in contact with the end wall 16 While the folding die 44 advances over the top and bottom of. the form folding the flap 19, tabs 2% and bottom flange 26 to overlap marginal areas of the assembled blank 4. The die 44 is provided with heating means with which to activate the thermoplastic adhesive on the areas comprising the tabs 24 and flange 26 which areas are united with the corresponding areas of the blank 4. The area covered by the folded flap 19 between the united tabs 24 is lightly compressed. The die 44 irons tie material and draws it tightly over the corners of the end wall 16. Following the advance of the die 34 the longitudinal flanges '32 and 36 of the assembled blank 5.5 (Fig. 6) are contacted with heating irons which are equipped with electrical calrods 4-8 which are connected with a source of electrical current and thermostatically regulated to-rnaintain the desired temperature. The irons 47 are-operated in a substantially straight-line motion by being mounted to bell-crank arms 49 and 49a and arms 50 disposed parallel to arms he irons 4'7 oppose each other in pairs top and bottom in relation to the form 13. The bell-crank arms 49 of each pair of irons are connected with a floating pin 51 at the center of the opposed conecting bell-crank arms 49.4. A fork 52 carries the pin 51, the fork is mounted to a rod v53 which connects with a suitable cam lever (not shown) and given motion by a suitably contoured camv The parellel arms 49 and 59 have fulcrums 54 and 55 respectively, mounted in asuitable housing 56. The irons 47 are counected with the arms 49 and 59 with pins 57 and 58 respectively.

The faces 5-9 of the heating irons 47 wipe the exterior surfaces of the extending longitudinal flanges 3?: and 36 of the assembled blank 15 to first preheat and soften the thermoplastic adhesive on the inner surfaces of the said flanges. The rods 53 pull the connected bel -c1 arms49a in-semi-toggle like motion which move the pairs of irons 47 inwardly in opposing directions on a substam tially straight line, folding the flanges 32 and 3d of the assembled blank 15 (Fig. 7) in overlapping relationship with marginal areas of the assembled blank 4. The inwardly opposed straight line motion of the sealing irons 47draw the said flanges tightly over the edges 69 of the assembled blank 4 (Fig. 8), forming scaled abntmcnts of the said edges to the interior wall surfaces of the folded blank 15. The ironing action of the scaling irons 47 unite the flanges 32 and 36 to marginal arc of the as sembled blank 4 in an eilicicnt and expeditious !-"lfll3l which reinforces the container structure and avoids e:';- posure of raw edges of material. Within the in erior of the container. Paper-board when folded has inherent characteristics of fracturing or minutely cracking at the folded junctions. When the paper-board is coated with film, such minute fractures damages the efliciency of such film. The method employed by the present invention overcomes these characteristics, the thermoplastic film on the material is first pre-hcated and then folded over edges of material that tightly engage the interior radii of the folded junctions of material in edge to face relationship. The ironing and drawing co-action of the sealing irons avoids the common defects of compressing and squeez mate rial which would otherwise flatten out the matcri: of the overlapping flanges and disengage the edge abutments of mat rial- The sealing irons 47 are withdrawn from the completed seams by being moved transversely therefrom with respect to the straight-line motion, retracting off the surfaces of the flanges before retracting outwardly to the original starting position of the irons.

While folding the flap 19, tabs 24, flange 26 and longitudinal flanges 32, 36, the V-shaped notches at the four corners adjacent the central end wall areas 16 of the container are closed in tight abutments 61 (Fig. 4), the blunt apices 23 and 28 of the notches forming excess material 62 at the corners which is compressed with heat, sealing and reinforcing the end wall corners of the container structure.

The sealing irons 47 (Pig. 6) remain in an upwardly disposed initial position shown in dotted arrow lines to provide clearance for the form 13 with the assembled blanks to move in position to be worked upon. The housing 56 may be provided with means to move the sealing iron assemblies in a transverse motion with respect to their straight line motion as shown by the dotted lines of the vertically disposed arrows shown in Fig. 6.

The form 13 may be arranged in multiples mounted upon a turret adapted to move the forms in various station positions to be worked upon. The heat from the sealing irons moves through the material, while forming the container seams, into the form. The heat will build up in the forms to temperatures that may become injurious to the plastic film coating on the interior surfaces of the assembled blanks. The accumulation of heat may activate the plastic film causing the material to adhere to the surfaces of the form and destroy the efiiciency of the containers as well as the efiiciency of scam forming operation. Provisions are made to obviate such consequences by providing a cooling medium to contact the form at the finish of each cycle of container forming operations.

Upper and lower shoes 63 (Fig. 9) are provided with chambers 64 through which cold water may be circulated .or, the chambers may circulate a refrigerant material adapted to cool and maintain a thermal balance of temperature of the forms. The shoes 63 are adapted to open and close, closing upon surfaces of the form 13 after the completed container is ejected therefrom and prior to the assembly of the next succeeding pair of blanks. Thus the temperature of the forms are controlled and kept from overheating.

The completed containers as ejected from the forms have plastic film on the interior surfaces of the walls. The seams of the container as described hereinbefore are constructed to avoid exposed edges of material within the interior of the container. The edges of the first blank are sealed to inner marginal areas of the second blank, the containers are therefore rendered liquid tight having interior Walls and corner junctions thereof that are substantially impervious.

The containers of the present invention may be fabricated with plain walls (uncoated) and then treated to be rendered impervious by spraying the interior walls of the container with resinous plastic film such as Saran or vinyl compositions and dried with heat which sterilizes the containers which are then nested together to maintain sanitary condition.

The containers may alternatively be fabricated of plain paper-board and after assembly, be treated and sterilized with hot liquid microcrystalline and parafiine wax.

The containers are hermetically capped after filling, the capping operation consisting of preparing pre-cut blanks which may be fed from a magazine to the capping dies or, the blanks may be cut from a roll of sheet material adapted to feed the said capping dies. The sheet material with which to form the caps to the containers may be of any suitable sheet material. Aluminum foil about 0.004 inch thickness is preferred, the adhesive for uniting the cap closure with the mouth of the container being supplied to the wall areas constituting the mouth of the container.

A strip of such cap sheet material 66 provides a blank 70 (Fig. The strip is pre-cut with a pair of notches '6 66a centrally located to aline 67a transversely disposed to the feeding direction of the strip. The notches may be used to pilot the strip to a central position with respect to the cap forming dies. The blank 70 is cut from the strip 66 on a medial line 67 disposed at the center of the transversely disposed base edges 68 of the notches 66a. The four corners of the blank 70 have curved edges 69 which join edges 68 and 71 disposed at right angles to each other. Marginal areas of the blank 70 consist of an unbroken area 73 surrounding a closure panel area 72 and extending around four sides of the blank defined with parallel bending lines 74, 75 and transversely disposed bending lines 76, 77 and broken areas 78 defined by bending lines 75 and edges 67 extending between the corner edges 68, and edges 79 extending between the corner edges 71 of the blank.

The completed container 65 (Fig. 12) is illustrated with the cap 70b united to the container and ready for service. The capped end of the container now becomes the base of the container (Fig. 14), the hermetically sealed dispensing closure at the opposite end of the container serving as the top of the container. The container (Figs. 14 and 15) may be opened with the fingers by grasping the flap 19 pulling same outwardly and upwardly to efiect a release of the flap from the spring-like clamping flanges 34 which are free to spring outwardly sufiicient' to release the flap. Further upward movement of the flap severs a portion of the top area of the end wall 16 on the perforated cut lines 25. The area severed removes the tongue 12 on the cut lines 11 exposing an opening 93 through the inner end wall 5 of the container v(Fig. 15) with which to pour or dispense the contents of the container. The opening 93 may be closed and firmly retained in closed position by inserting the end of the flap 19 inside the clamping flanges 34, pushing the flap downward for the tongue 12 to re-enter and close the opening 93. The ledges 94 in the flap 19 latch to the horizontal edges 20 of the tabs 24. The clamping flanges 34- retain the said latched engagements. The groove 43 (Fig. 14) provides an eflicient hinge upon which the fiap 19, when raising, will pivot to avoid disorderly bending or buckling of the paper-board'material. The latching connections 20 and 94 of the flap and tabs 24 overpowers the inherent spring in the board material and hence draws the severed flap substantially tight over the opening 93. This facility serves to keep extraneous odors from entering into the container contents after the hermetic seal of the dispensing closure has been initially broken.

The container and methods constituting the invention disclosed herein has many attendant advantages that will be understood from the foregoing description, and it Will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention, the form hereinbefore described representing a preferred embodiment thereof.

I claim:

1. The method of making paper containers comprising folding a first blank over three sides of a substantially rectangular form, said blank consisting of an end Wall and opposing longitudinal side walls having edges adjacent to the corners of the form, said first blank being coated with thermoplastic material, folding a second blank having an end wall and opposing longitudinal side walls and end wall flange extensions and also a thermoplastic material thereon over said end wall of the folded first blank and over the exposed form surfaces, said second blank having longitudinal marginal areas adapted to be superimposed upon longitudinal marginal areas of the first blank, heating the overlapping end walls, applying pressure simultaneously with said heating to said end walls in varying degrees to selected areas to effect a permanent union of the selected areas having the greater pressure and temporary union of the other areas, heatironing the flanges of the exterior end wall over the under- 7 lying portions of the first folded blank, and drawing said flanges of the said exterior end wall simultaneously with said ironing.

2. The method of claim 1 comprising heat-ironing the longitudinal marginal areas of the container sides of the second blank over the longitudinal marginal areas of u c first blank, and drawing said superimposed marginal areas simultaneously with said ironing over the longitudinal marginal areas of the first blank to effect a sealed reinforced impervious and permanent seam.

3. The method of claim 2 comprising heat-i oning the longitudinal marginal areas of the container sides of the second blank over the longitudinal marginal areas of the first blank, wherein the direction of ironing is a substantially straight line parallel to the surface being ironed, and proceeds in one direction while ironing the said superimposed marginal areas.

4. A method of making paper containers by folding paper blanks over a form adapted to shape the container, said form having a suction chamber therein provided with suction openings to the exterior of said form, com prising creating a suction in the chamber of said form, folding a first blank having an end wall and two opposing side walls over said form, suction gripping the longitudinal side walls of said first blank to said form, folding a second blank having an end wall and opposing longitudinal walls over said form having said suction gripped folded first blank thereon, suction gripping the longitudinal side walls of said second blank to the walls of said form, said second blank having side walls with marginal areas extending beyond the walls of the form, preheating said marginal areas extending beyond the form, drawing the said marginal extended areas to overlap the exterior surfaces of the walls of the first folded blank, and ironing said overlapping margins in opposed inward relation to effect thermally united longitudinal seams.

5. The method of forming overlapping longitudinal seams on paper containers having flat wall surfaces, said walls having thermoplastic adhesive thereon, said container having a first blank disposed on a form, and a second blank disposed about said first blank with marginal extending areas disposed beyond said first blank, comprising moving a pair of heat-sealing irons to engage the outer Walls of said marginal areas, heat wiping the outer walls of said marginal areas to pro-heat them, moving two facingly opposed marginal areas inwardly, simultaneously drawing the said marginal areas of the second blank over the marginal edges of the said first blank and causing edge portions of said first blank to abut in sealed non-wicking contact against face portions of said first blank, heat-ironing said overlapping marginal areas by a flat hot ironing surface moving in a direction parallel to and contacting fiatwise therewith the surfaces ironed, lifting said sealing irons off the ironed marginal surfaces in a direction at right angles to the ironed surfaces, and retracting outwardly the said sealing irons to their original position.

6. A method of making containers adapted to retain liquid and having impervious thermoplastically adhered seams composed of a first wall portion disposed in approximately right' angular relation to a second wall portion with an edge of said first wall portion abutting an opposing face of said second wall portion and a flange extending from said second wall portion over said edge and sealed against the adjacent outer face of said first wall portion, said method comprising bringing said wall portions into said right angular and edge and face abutting relation with said flange extending beyond said edge, ironing with heat said flange over said edge and against the outer face of said first wall portion, and drawing simultaneously with said heat ironing said flange fiatwise against said first wall portion to firmly seal the edge in non-wicking contact against said second wall portion.

7. A method of making containers adapted to retain liquid and having impervious thermoplastically adhered seams composed of a first wall portion disposed in approximately right angular relation to a second wall portion with an edge of said first wall portion abutting an opposing face of said second Wall portion and a flange extending from said second wall portion over said edge and sealed against the adjacent outer face of said first wall portion, said method comprising bringing said wall portions into said right angular and edge and face abutting relation with said flange extending beyond said edge, first preheating the extended flange and then ironing with heat said flange over said edge and against the outer face of said first wall portion, and drawing simultaneously with l heat ironing said flange flatwise against said first wall portion to firmly seal the edge in non-wicking contact against said second wall portion.

8. In a container of foldable paperboard sheet material having four side walls arranged in opposing pairs to provide a body portion of substantially horizontal rectangular cro ection and a Hat two-ply closed end, each ply being hung at with each of two pair of alternate side walls, which walls are coutiguously joined together at their vertical edges by overlapping flanges, said closed end comprising the inner Wall. layer having an elongated lJ-shape semidctachable section cut through said wall substantially central of parallel corner edges thereof, the outer wa l layer of said end overlapping said inner wall layer in selective adhesive surface bonded engagements and having a pair of perforate lines spaced outwardly of the border lines of said semi-detachable cut section, which cut section is securely bonded with said overlapping wall to form a two-ply openable and reclosable end closure, said outer wall having two opposed integral side flanges transverse of said perforate lines and being folded downwardly transverse of the corner edges thereof and in adhesive contact with exterior surface portions of each wall of a pair of alternate side walls, one flange of said pair having a pair of substantially transverse continuous lines cut therein to define two opposed outer and upper end bonded portions thereof including lower detachable corresponding portions adapted to be separated from said upper portions by said out lines, which lines are each arranged with horizontal slit edges extended inwardly of the end side edges of the flange and being further extended upwardly and outwardly to join substantially with terminal ends of each of said perforated lines in said outer wall substantially at the folded corner end junction of said flange with said top layer, said outer opposed lower detachable portions of the flange being overlapped by yicldable inner opposed portions of a pair of overlapping flanges, said yieldablc flange portions being adapted to prevent discngagcments of said edges defining said upper and lower cud portions of the flange having said lines cut therein except by manual manipulation of said to open the closure upon separating said cut lines and severing said perforated lines.

9. in a container according to claim 8 wherein said horizontal slit edge portions of the cut lines that define said bonded upper and detachable lower portions of the flange co-act with said yieldabic vertical flange portions, which yieldable portions overlap said lower portions in a manner adapted for keeping the slit edges in edge to edge abutment before and after opening at l tor the closurc said edge to edge engagement provio 3g positive locking means to overcome the inherent spring characteristics of the material of wall portions that open said closure and upon being restored, retain said portions substantially in original fixed position with respect to other wall portions of said closure.

ii). A container of paperboard treated for holding liquids and having four side walls arranged in opposing pairs, each pair being joined to the other pair along their contiguous vertical edges to provide a body port: it of substantially square horizontal cross section and hazing a uniform flatly closed end wall adapted to provide dispensing means for the liquid contents of the container, which comprises one pair of said side wal s having a fiat integral end wall disposed at substantially right angles of said side walls, the end wall being provided with a substantially central U-shape section slit through said wall, the other pair of side walls having a flat integral end wall in overlapping surface relation with the first named end wall and being in selective adhesively bonded surface relationship, the outer end wall having a pair of opposed perforated lines spaced outwardly of the sides of said slit section in the inner end wall, said outer end wall being also provided with a pair of opposing transverse integral wall margins constituting front and back flanges folded downwardly of the top plane of said outer end wall and being engaged in selective adhesively bonded surface relation with upper marginal portions of said first mentioned one pair of side walls, said front flange having a pair of opposed cut lines slit inwardly, upwardly and outwardly in terminal connections with said perforate lines in the outer end wall, said slit lines defining outer upper bonded portions of the flange and detachable lower sides including a central wall portion thereof, said upper portions having outer end edges sloping inwardly and downwardly in edge to edge abutment with corresponding inner side edges of a pair of inwardly opposed vertical side wall flanges that form said contiguous relationship of the side walls of the container, the lower end of each sloping edge of said vertical flange continuing inwardly in substantial horizontal plane to define a free lower yieldable portion thereof, which portion overlaps said lower detachable sides of said front flange, said engagements providing means to keep said upper and lower flange portions in edge to edge engagement and in coplanar surface relationship and thereby prevent separation of said upper and lower portions of the flange except by the manual release of the central wall portion thereof from said free yieldable portions of the other flanges.

11. A container according to claim wherein the parallel slit line portions of said U-shape section and said parallel perforated line portions that are disposed in said end wall being terminated therein by meeting engagement with a transversely disposed embossed groove extending between the terminal ends of said perforated lines and said groove being spaced inwardly of a parallel corner edge of said end wall, the embossed groove providing means with which to form a bending hinge from which to swing the portions of said end wall defined as being intermediate of said slit and perforated lines when opening the end wall for container content dispensing after said perforated lines are severed and slit lines separated, said bending hinge providing means to restore the closure in said end wall in registering position by causing the edges of said slit lines that define outer upper bonded portions of said flange and detachable lower sides thereof to register said edges in abutment and thereby lock and secure the restored closure substantially as structurally initiated.

References Cited in the file of this patent UNITED STATES PATENTS 515,121 Hunt Feb. 20, 1894 1,057,091 Rosenkranz Mar. 25, 1913 1,217,694 Bracy Feb. 27, 1917 1,280,364 Armstrong Oct. 1, 1918 1,342,575 Wentworth June 8, 1920 1,708,828 Bremrnerman Apr. 7, 1929 2,019,412 Hendrickx Oct. 29, 1935 2,125,620 Schlumbohm Aug. 2, 1938 2,234,167 Hothersall Mar. 11, 1941 2,249,657 Junkin July 15, 1941 2,276,577 Hahn Mar. 17, 1942 2,323,505 Wilcox July 6, 1943 2,386,787 Geersteen Oct. 16, 1945 2,403,995 Peters July 16, 1946 2,423,965 Coyle July 15, 1947 2,437,114 Moore Mar. 2, 1948 2,452,952 Palmer Nov. 2, 1948 2,576,446 Condon Nov. 27, 1951 2,581,237 Casler Jan. 1, 1952 2,620,944 Stahl Dec. 5, 1952 2,626,495 Gaubert Jan. 27, 1953 FOREIGN PATENTS 600,560 Germany June 17, 1933 

